A common flushing apparatus for toilets involves a reseating flush valve that holds a large volume of supply water in a tank from which it is suddenly released into the toilet bowl. And, a float valve is responsive to the water level in the tank to replace the water level, operating automatically and separately from the flush valve that is manually operated by movement of a flush handle or lever that is turned to lift the flush valve. A detrimental feature of this common system is that the flush valve tends to and eventually leaks, resulting in continued water waste.
Another flushing apparatus, common in the United Kingdom, involves a syphon tube having its suction leg depending into the supply tank so as to be filled with water, and its discharge leg normally empty of water and opening into the toilet bowl, and operated by means of a primer pump that is manually actuated to fill the discharge leg thereby initiating syphoning. The said primer pump operates as a water lifting means in the suction leg of the syphon, and the advantage of this syphon system is that there can be no leakage from the supply tank through the inactive syphon. Another feature of the United Kingdom toilet flushing apparatus is the prescription of a "Warning Pipe" flush tank overflow specified to be 6.sub.4 mm or 21/2 inches below the bridge of the syphon, thus determining the maximum water level in the flush tank.
In view of the foregoing, it is an object of this invention to employ the aforesaid syphon tube flush principle of operation to the exclusion of a pump means, and replacing the aforesaid pump-type primer means with a tank-type primer means and flush valve in combination with a suction check valve that is operable with toilets having a "Warning Pipe" prescribing supply tank water level to be substantially lower than the syphon bridge.
The syphon principle of operation is superior with respect to the conservation of water, in that there can be no continuous leakage therethrough when its discharge leg is empty of water. And only when the discharge leg is primed does water flow therethrough. On the contrary, the conventional flush valve principle of operation is prone to continuous leakage from the water supply tank and through the flush tube, due to deterioration of either the valve seat or valve ball. It becomes apparent therefore that the syphon principle is superior, except for the inevitable deterioration of the pump means therefor which is a flap or disc of flexible material that lifts the tank water into the syphon and initiates continued flow therethrough until the water supply tank is emptied through the flush tube. Accordingly, these two widely used principles of operation are each subject to deficiencies, one to inherent leakage and the other to eventual inoperation. In view of the foregoing, it is an object of this invention to provide a toilet flushing apparatus that virtually eliminates leakage of the flush water, and that provides automatic refilling of the primer tank for repeated flushings.
It is also an object of this invention to employ the aforesaid syphon tube principle of operation to the exclusion of a pump means, and replacing the aforesaid pump-type primer means with a tank-type primer means, flush valve and suction check valve.
It is to be understood that the water supply tank is refilled after each flushing operation, or incomplete flushing operation, by means of a conventional and accepted water level responsive valve means from a water supply service pipe. In practice, a float controlled valve returns the tank water to a level below the "Warning Pipe" and substantially below the bridge of the syphon after each flushing operation, complete or incomplete. And it is this float controlled water that overflows from the primer tank and automatically refills the supply tank.
Referring now to the prior art as represented by my U.S. Pat. Nos. 5,113,536 and 5,109,552; my earlier filed '536 patent entitled Jet Activated Toilet Flushing Apparatus discloses a toilet flushing apparatus characterized by an inherently leakproof syphon, primer and flush tube aligned with a flush pipe into the toilet, with a jet opening from the discharge of the syphon to initiate flushing when a charge of water is manually dumped from a bucket and through the flush tube; and, my later filed '552 patent entitled Primer Tank Toilet Flushing Apparatus discloses a toilet flushing apparatus characterized by an inherently leakproof syphon, a manually discharged primer tank initiating syphoning through a discharge tube and toilet flush tube, and with a floating flush valve and control for complete discharge of primer water followed by immediate closure to ensure continued syphoning, the primer tank being automatically refilled with the rise of float controlled supply tank water.
The syphon principle of operation is characterized by two conditions, a passive condition wherein the suction leg has a water level substantially below the bridge and the discharge leg is dry, and a functioning condition where the suction leg and discharge leg are flooded. In order to achieve said flooded condition of the two syphon legs, priming is required for completely filing the otherwise low level suction leg before flooding the dry discharge leg, whereby syphoning action is initiated and continues to occur. It is an object of this invention to sequentially prime the two syphon legs by discharging a relatively small volume of water sequentially into the suction leg and then into the discharge leg, so as to initiate the syphon effect. In practice, flooding of the two syphon legs enables the syphon to function with sudden high velocity of water therethrough.
The sudden termination of primer tank water and closure of the syphon to atmosphere before air enters therein is a prerequisite to successful flushing, and to this end it is an object of this invention to provided flush valve control means by which the flush valve closes as and when the primer tank water is depleated, thereby shutting off the outside atmosphere for continued syphoning.
The flush valve is a conventional floating ball type valve. In practice, shut-off is by means that lifts and drops the flush valve. As shown, the primer tank is fixed and flushing control relegated to the flush valve and reliant upon water supply of float valve filling of the supply tank. However, in the event of a flush valve leak or malfunction, the primer tank water can be lost, but only this small quantity of water can be wasted.